242 University of California P uhlications in Botany [Vol. 6 



smooth, color yellow streaked with red, or entirely red. Context of 

 the stipe is of the same color as that of the pileus. 



These plants are distinguished from Form B by the .shape of the 

 stipe and by the fact that the context does not change to blue when 

 exposed to the air. 



It is a remarkable fact that a young- individual about 1.3 cm. in 

 length collected with these plants showed a distinct veil. In older 

 individuals this veil completely disappears, leaving no trace either as 

 an annulus on the stipe or as a fringe on the margin of the pileus. 

 This is the only form of Ceriomyces communis of which I have a 

 specimen showing the presence of a veil (No. 241), though I have a 

 suspicion, which is not, however, verified by actual specimens, that 

 a veil exists in certain, if not all, of the other forms of C. communis, 

 of which I have .seen living material. 



^o 



Histology 



In form E the pileus is covered with an outer layer 60 to 80/x, in 

 thickness formed of separate hyphae 20 to 30^ in diameter. The walls 

 of these hairs are light brown in color. Beneath the hairs is a dark 

 brown tissue made up of densely interwoven hyphae 2 to 4/i, in diameter 

 and frequently branching. The second layer is about 16 to 20^. in 

 thiclcness. Below these two layers is the context, composed of inter- 

 woven hyaline hyphae 4 to 8/x in diameter (pi. 23. fig. 16). 



The structure of the hymenium and of the rind and context of 

 the stipe are exactly the same, as has been described in the case of 

 Form B described above. 



Ceriomyces crassus Batt. 



Ceriomyces crassus is another species commonly occuring in the 

 Bay region of California. The plants are found growing on the ground 

 among decaying leaves and twigs under redwood {Sequoia semper- 

 virens) , tan oak {Pasania densiflora), Douglas fir {Pseudotsuga tax- 

 ifolia) , and madrone {Arhutus Menziesii) . Unlike certain other species 

 of Boletaceae, the plants referred to Ceriomyces crassus do not appear 

 to be restricted to the vicinity of any particular genus or species of 

 the higher plants." The plants u.suall}^ appear only after the first rains, 

 which generally come in October, and they remain above ground only 

 a short time, though occasionally one may find them until December. 

 Form C described below was, however, collected February 1, but as 



